The Taklamakan Desert, located in northwestern China is hiding one of the world’s largest underground carbon sink in the form of an ocean.
Surprising as it may be for one of the world’s driest regions, researchers found that carbon dioxide emissions in the Tarim basin could not be accounted for. They set to understand what makes carbon dioxide emissions, greatly contributing to climate change, disappear without a trace here.
By sampling 200 different locations in the Tarim basin, the Chinese researchers found that underneath the arid soil, a massive ocean captures the greenhouse gas emissions effectively. According to their conservative estimations, the amount of water present in the underground basin could amount to more than North America’s all five Great Lakes put together.
Professor Li Yan of the Xinjiang Institute of Ecology and Geography at the Chinese Academy of Sciences and lead author of the study stated:
“Never before have people dared to imagine so much water under the sand. Our definition of desert may have to change”.
The study is published in the Geophysical Research Letters journal.
A basin is defined as a valley collecting water from all drainage systems connected to it. In the case of the Tarim basin, which is also bordered by the Tian Shan Mountains to the north and Kunlun Mountains to the south, the snow blanket drips into the basin as it melts.
However, one will never see water captured here. The basin is dry as is the Taklamakan region.
A possible explanation given by the researchers is that agricultural practices dating to 2,000 years ago might have influenced the creation of the carbon sink. Water from the basin was fully extracted to irrigate crops, living the basin dry. Still, water creeps underground and in time, it created the large carbon sink in the form of the underground ocean.
It seems that fertile soils in the region are as salty as the water in the underground basin. This is an indication that the same carbon dioxide infused water has been used for irrigating the land for centuries.
“As a result, agricultural development over human history has enhanced the carbon sink”,
conclude the authors of the study.
In the 200 locations where samples were collected, the researchers found that the underground water is rich in carbon dioxide.
Each year, the amount of carbon released in the atmosphere reaches approximately 11 billion tons. Of these, 5 billion tons linger in the atmosphere, adding to the greenhouse effect. Three more billion tons are captured by the oceans of the planet. Two billion tons are thought to be sequestered by forests. However, one billion tons could not be accounted for by specialists.
The Tarim basin in the Chinese Taklamakan desert is part of the answer for the mysterious carbon sink riddle.
Typically, carbon sinks are either oceans or regions with dense vegetation. Deserts are quite a surprising finding. Possibly, the Tarim basin is not the only one hiding an underground carbon sink in the form of a large aquifer.
The analysis of underground water samples collected from this region showed that the hidden aquifer is more efficient in capturing carbon dioxide that the on-land vegetation. According to the estimates, desert underground aquifers are capturing 14 times more carbon dioxide annually than previously thought.
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